Furnace



Jmzs, 1941. H. w. KELLY 2,230,040

' FURNACE Filed Oct. 2, 1940 Patented Jan. 28, 1941 PATENT ot'rics FURNACE Herbert W. Kelly,

Chicago,

Ill, assignor to Meehanite Metal Corporation, Pittsburgh, Pa", a corporation of Tennessee Application October 2, 1940, Serial No. 359,429

. 6 Claims.

The present invention relates to furnaces and more particularly to means for supplying air to metallurgical furnaces, such as cupolas and the like The usual type of cupola is provided with an I air chamber commonly known as a Wind boat or wind belt, which surrounds the shaft of thecupola and directs the blast of air to the tuyeres.

In all cupolas, as heretofore constructed, the

blower or fan for creating the blast of air is placed at a considerable distance from the cupola, and the supply of air from the blower to the wind box is usually by means of a long pipe or blast main which conducts the air to the wind box along a F plane tangential to the wind box. with such a system, the air assumes a swirling or tangential motion in the wind box, with accompanying varying velocity in different portions of the cupola as the air meets the tuyres. Furthermore, because of the joints and bends in the pipe or main,

frictional resistance and leakage of air is err- I portions of the wind box.

countered which further decreases the efficiency of the cupola.

The present invention is designed to obviate these objectionable features by eliminating the long air carrying pipe and providing air supply means located directly at the cupola and arranged to supply air uniformly around the same. In the preferred embodiment of the invention, a fan or blower is mounted directly at the wind box and disposed to supply air uniformly around its entire circumference thus dispensing with all or the incidental equipment that is the chief source of difficulty in cupola operation. Thus, the present invention eliminates the long air pipe and supplies air directly and uniformly into all This produces an equal velocity and diffusion of air into each tuyere, which is not possible by the prior constructions.

The present invention has the additional advantages of low maintenance and low installation cost. which may be readily applied to any standard design of cupoia.

A further object of the invention is the provision of a fan which will not only provide anequal distribution of air to the tuyres, but will also permit the volume of air to be increased or decreased by controlling the speed of the fan.

With the foregoing and other objects in view.

the invention will now be more fully described, reference being bad to the accompanying drawing in which:

It furthermore comprises a compact unit- (Cl. cos-3o) Figure l is a side elevation partially broken away oi the present invention;

Figure 2 is a section on line 22 of Figure 1;

Figure 3 is a section on line 3-3 of Figure 1;

Figure l is a vertical section through the tan or blower, and

Figure 5 is a vertical section through the furnace.

Referring now to the drawing, the numeral it designates generally a furnace to which the present invention is applied. This furnace has the usual cupola body or shell it which is in the form or a cylindrical shaft, the inner walls being lined with fire bricl: it. The shell or body it and the brick lining it are mounted upon a bottom plate it which, in turn, is supported upon legs it. For purposes of simplicity and because they do not constitute any part of the present invention, the usual top and slag holes are not shown. Furthermore, such elements as the clean out door, breast arch, and drop bottom doors are not illustrated, but it is to be understood that the cupola it: is provided with all of the parts necessary lop/the emcient operation of the same.

A plurality of tuyeres it are provided adjacent the lower end of the furnace, and these may be of any desired number and configuration. Surrounding the cupola' body it is a wind box it which also may be of the usual shape and cone figuration; that is, it is provided with an annular vertical wall ll spaced from, and extending parallel to the cupola body and having a bottom horizontal wall it. This bottom wall may be welded or secured to the body ii in any desired manner.

The wind box it is entirely open at its top. This distinguishes from the usual type of wind box which is usually enclosed with the exception of certain openings in its vertical wall which communicate with the pipes by which a flow or blast of air is introduced into the boa: from a blower positioned at a distance to the turnace. The open upper end of the wind box It is provided with an outer annular flange or ring l9. As illustrated in Figures 1 and 5, this ring constitutes a separate element which is suitably secured to the wind box. However, if desired, the upper end of the wind box may be so formed that the element It is an integral extension of the extending wall 2| and a plurality of inwardly and radially extending blades 22. As shown in Figures 2 to 4, the blades 22 extend at spaced intervals around the wall 2| and are mounted thereon in an inclined position.

The fan 20 is provided with a horizontal flange 23 corresponding to the flange l9, and these flanges have ball races 24 and 25 respectively formed in their upper and lower surfaces. As shown in Figure 1, the fan 20 is supported directly upon the top of the wind box, with the ball races 24 and 25 in register. Balls 26 are mounted in these races so as to provide a ball bearing by which the fan may be easily rotated upon the wind box. In order that the fan or blower 20 may be rotated so that the blades will create and direct a current or blast of air downwardly into the wind box uniformly throughout the circumference of the box and through the tuyres l5,'the top surface of the flange 23 is formed to constitute a ring gear 21 (see Figures 1 and 2). A bracket 28 is suitably mounted on the outer face of the wall I! of the wind box, and this bracket supports an electric motor 29. A gear or pinion 30 is fixed to the motor shaft 3! and meshes with the ring gear 2l so as to impart rotary motion to the fan 20 when the motor is operated.

With the construction, as thus described, operation oi the motor will rotate the fan or blower 20 through the pinion and ring gear, and this will' rotate the blades 22 above the wind box and about the cupola body I I. This rotary movement of the blades will create a current or blast of air which will be directed downwardly into the wind box uniformly throughout the box circumference and through the tuyres l5. It is to be understood that the tuyres are equally spaced about the cupola body whereby rotation of the fan will develop sufficient air equally in each tuyere for proper combustion of the cupola fuel. In .this

connection, the air is drawn in from the upper side of the fanand then is forced down into the wind box to the tuyeres in equal amounts, In order to insure the air taking a downward direction, a plurality of bailie plates 32 are mounted vertically in the wind box. It is to be understood, however, that while these plates are desirable, they are not essential to the operation of the present invention and may be eliminated if desired.

Since varying factors, such as weather conditions, make it necessary to vary thevolume of air flowinginto the wind box, the motor 29 is provided with a rheostat 33 having an operating handle 34 by which the speed of the motor may be governed. Thus, by changing the speed of the motor, the speed of rotation of the fan or blower may be changed to secure the desired adjustment in air, volume to the wind box and tuyeres.

It will thus be apparent that the present invention constitutes a considerable improvement system of remote air supply.

over the prior art by'entirely eliminating the long pipe or main for supplying air to the wind box,

.and its accompanying objectionable features, such as unequal and varying velocity of air to the tuyres. The present invention, by supplying air directly and uniformly to all portions of the wind box, insures an equal velocity and diffusion into every tuyre, which is not possible by the prior It is to be understood that the furnace to which the present invention is applied is representative of the usual type of cupolaL furthermore that such changes and adaptations from the particular construction herein disclosed, as are within the skill of the mechanic, may be made without departing from the range of this invention,

I claim:

1. In a furnace having a wind box for supplying a blast of air to a plurality of tuyeres, means movably carried by saidfurnace and rotatable circumferentially thereof for creating and directing a blast of air into the wind box uniformly throughout its circumference.

2. In a furnace having a wind box for supplying a blast of air to a plurality of tuyres, means movably mounted at the wind box and rotatable circumferentially of the furnace for creating and directing a blast of air into the wind box uniformly throughout its circumference.

3. In a furnace having a wind box positioned around the body of the furnace for supplying air to a plurality of tuyeres entering the furnace, a circular fan surrounding the body of the furnace and rotatably supported at the wind box and extending circumferentially of the furnace, and a motor operatively connected to said fan to rotate thelatter on the wind box and create and direct a blast of air into said wind box uniformly throughout its circumference.

4. In a furnace having a plurality of tuyres entering the furnace, a wind box positioned around the body of the inmate for supplying air to the tuyres, said wind box being open at its to the tuyeres, said wind box being open at its top, and a circular fan rotatably mounted at the wind box and extending circumferentially of the furnace for creating and directing a blast of air into the'top of the wind box uniformly throughout its circumference, said wind box being provided with a plurality of substantially vertically positioned bailles to facilitate in directing the blast .of air uniformly to the tuyres.

6. In a furnace having a plurality of tuyres entering the furnace, a wind box positioned around the body of the furnace for supplying air to the tuyeres, said wind box being open at its top, and a circular fan rotatably mounted at the wind box and extending circumferentially of the furnace, said fan comprising an outer annular wall, and a plurality of radial blades connected to the inner face of the annular wall and adapted when the fan is rotated to create and direct a blast of air into the top of the wind box uniformly throughout its circumference, a ring gear fixed to the fan exteriorly of the annular wall, and a motor having a pinion mounted on its drive shaft and meshing with said ring gear to rotate the fan.

HERBERT W. KELLY. 

